The same crop tool functionality used on images works on videos. By default, the Video Shape tool crops to the existing rectangle aspect ratio. To make the video playback a perfect circle, use the crop tool to manually change the aspect ratio to 1:1.

Note: adjust the viewable area of the video by repositioning the video in the cropped area while the crop tool is selected.

The video is now a circle, or a star, a heart, or any other shape in the Video Shape library!

Whichever shape you select, the video will export and play in that format.